Clocking in or out of a Project is done by using the Punch Clock tool found within Projects.

When a project is open click on the Punch In icon to Punch In and click on the Punch Out icon when you have finished your work. Your hours will be associated with the Project you have open.

The second way to Punch into a Project is through the main Punch clock found in the Quick Access toolbar.

The Punch Clock will pop up and you will be able to specify a Project(labeled Case) based on the Projects your profile has access to. The Case field will list all Projects you have created or are assigned to so highlighting and clicking on a specific project will clock you into that Project. Clocking out on this Punch clock or from within Projects will clock you out of that Project as well.

Please note that when the Punch Clock comes up you will know if you are already clocked in by which of the 'Punch in' or 'Punch out' icons are live. If you have already Punched in the only option you will have is the 'Punch out' icon to click on.